Over 200 million people worldwide are infected with HepC. The drug Sofosbuvir presently seems to offer the best chance of a cure. The production cost is about $1 a pill, one a day being taken for a 12-week course along with other relatively inexpensive medicines. In the UK the price that the NHS would pay for such a course of treatment is currently about £35,000.
A firm called Gilead Sciences had bought the patent for the drug, paying $11 billion to a startup company, Pharmasset when their results showed promise. Their development of the drug had in turn been based on a research breakthrough at Cardiff university which had not been patented.
Sofosbuvir came to the market in 2013. By the first quarter of 2016 Gilead had collected £35 billion in revenue from HepC medicines.
There are maybe 5 million people with HepC in the USA alone, and Gilead is asking $84,000 each for its treatment. That's a total in Zuck's own back yard of more than a hundred times his £3 billion for just a single disease. It's not money that needed, it's an ethical approach to medicine.